Scarificator



Feb. 20,

I )a 32 y l. R. MORRISON SCARIFICATOR Filed NOV. l0, 1949 Wwf/M @E f/w Marr/50,7

Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE SCARIFICATOR Ira R. Morrison, Atchison, Kans.

Application November 10, 1949, Serial No. 126,542

(Cl. 12S-333) 14 Claims.

supercial abrasions are made in the epidermis,

care being taken not to scratch deep enough to draw blood; allergens (i. e., extracts of the various materials suspected of being possible oifending agents) are applied to the abrasions and the patients skin reaction to the different substances is observed. It is, of course, very important that the scratches be of uniform length and depth in order that the results of different tests can be compared and proper diagnosis made on the basis thereof.

Most allergists heretofore have been making the necessary scratcheswith a needle, sharp or semi-sharp cutting instrument; however, it takes a highly skilled technician to produce the type of scratch needed, and even those who are Well trained find it difficult to produce scratches of uniform size and depth. A novice usually nds it impossible to consistently produce uniform and proper scratches. l

It is, therefore, an object of the invention to provide an improved instrument designed for allergy scratch tests which insures scratching the epidermis or outer layer of skin without drawing blood.

Another object of the invention is to provide a scarificator that will produce an essentially painless scratch and therefore may be used without difficulty on children and adults hypersensitive to pain.

A further object is to provide a device that will consistently reproduce a scratch of uniform length and depth into the epidermis.

Still another object of the invention is to provide an instrument of the character indicated which requires little or no technical skill on the part of the operator, and hence, even in the hands of an untrained novice, gives consistently successful and uniform results.

A still further object is to provide a scaricator that is adjustable to produce scratches of different depths to accommodate same in the texture Oi v the patients skin, depending upon age, body location and general skin texture.

Other and further objects of the invention, together with the features of novelty whereby the objects are achieved, will appear in the course of the following description.

In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith, and in which like reference numerals are employed to identify like parts of the various views,

Fig. 1 is a side elevational view of a scariiicator` embodying my invention,

i Fig. 2 is a bottom view of the same instrument,A

Fig. 3 is an enlarged longitudinal cross section of the instrument taken along the line 3--3 of Fig. 1 in the direction of the arrows,

Fig. 4 is a sectional elevation of the instrument taken at from the plane of Fig. 3 and showing the mechanism in cocked condition,

Fig. 5 is a transverse cross section taken along the line 5-5 of Fig. 4 in the direction of the arrows,

Fig. 6 is a sectional view similar to Fig. 5 but showing the instrument in an uncocked or normal condition, and

Fig. '7 is a sectional elevation of a modied form of cutting element for my device.

Referring first to Fis. l. the basic elements of my scaricator comprise a knob or cap I0, a cylindrical case or barrel II and a base or skin contacting head I2. These parts may be knurled as shown. or otherwise surface marked to afford a good hand grip and facilitate manipulation of the instrument. Viewed as a whole. the instrument is an elongated. cylindrical unit only slightly larger than a conventional fountain ben.

Tightly fitted within the bore of the barrel I0 (for example with a force lit) is a sleeve-like liner I3 which in turn supports an axially slidable hollow stem I4. This stem projects from the lower end of the barrel and has the head I2 of my instrument screw threadedly .secured to its lower-most extremity. Encircling the stem between the head and the end of the barrel is a collar I5 and a cushioning washer IIS of rubber or rubber-like material. A coiled compression spring Il around the shaft with one end abutting against the bottom oi sleeve i3 and the opposite end in a cup-like recess in collar I5, urges the stem downwardly relative the barrel; the downward travel of the stem is limited, however', by a radial projection or stop i8, disposed in a 'longitudinal slot I9 cut in the sleeve I3. This slot knife blade Z3 which is disposed in a relatively deep recess or socket 212 in the head I2 with only the prongs 25 below the bottom surface plane ofV g the head.

The knife may be permanently secured in place' on the shaft, for example by welding, but preferablyit is frictionally held by the inward tension of the bifurcated leg of the shaft straddling it. In either case, it is held in spaced relation to the end of the stem i4 by an integral collar 2E? on shaft 22.

Fig; 'Z illustrates a modified forin'of.- cutting element that may be employed in placey of knife 2?. This comprises a tubular member 23d screw threadedly securedto` the lower end of shaft 22 in abutment with. thercollar 26. The lower end of the tube is cut ofi along twol oblique. intersecting planes to form points 25ct, these being sharpened and functioning in exactly the same way as will be described hereinafter in connection with the points of knife 23.

Returning now to the upper end'of the shaft 22,this is encircled by a coiled spring 2f! which has one end anchored in a.r slot 23y in the7 stem i4 .and the other end anchored to the shaft by passing it through a hole disposed crosswise (that is, the face of member i2) is pressed gently against the area of skin surface that has been selected to be scratched. This causes the points 25 of the knife to depress the epidermis very lightly. As the downward force on barrel H is increased, the head I2 can advance no further, being in abutment with the body, and instead, the barrel travels axially aV short distance relative to the stem ill as indicated by the arrow 36 which slides the catch 33 downwardly relative finger 281 until the finger is clear of the catch; as soon as this occurs,V spring 2i rapidly rotates shaft 22 (and with it, knife 23) back to the point where nger' abuts stop 36 as shown in Fig. 6. This rapid rotation causes points 5to travel a circular' path, scribng a slight, circular scratch on and into the epidermis.

therein, the-latter end extending beyond the shaft and forming ay radial iinger 29. The. spring is tensioned to apply a. torque on` the shaft tending to rotate same in a counter-clockwise direction as seen in Figs. and 6..

The rotation of thev shaft is limited to somewhat less than one complete revolution by stop 3B in the path of nger 2'5. This stop comprises a rubber bushing supported on an upwardly ,projecting lug 3| formed integral with stem ifi. The radial nger 29 also projects over the edge of sleevel3, a portion of which slopes upwardly as shown at 32 to form a step or' catch 33 spaced circumferentially from one side of stop 3B a suicient distance to permit finger 29 to occupy a pos'itionV therebetween as showni'n Fig. 5.

It will' be convenient at this, point to describe the operation of my scari'cator and the manner in which it is used incident to the makingl of allergy scratch tests. Assuming the parts are in uncooked position, as shown in Figs. 3 and 6, the barrel i@ is held in one hand, and, with the other hand knob [d is rotated clockwise (Fig. 6)' relative to the barrel until finger. abuts against the opposite side of stop Sil (see Fig. Y5)` VThe purpose of' this isr to wind spring 2 and then. hold theV shaft captive Vor in cocked condition with the spring wound under tension. During winding which it will. be seen requires somewhat less than one full turn of the knob, nger 25 'rides up the vinclined surface 32 drawing stem i4 axially of the barrel and Ycoi'mn'essing springv l?. `When the. finger passes the crest of the incline, spring il snaps the stem is and shaft 22 downwardlyv relative. the barrel bringing the finger between stop 'and the vertical edge or catch 33 so that shaft 22 now can turn in neither direction. The instrument now is in cocked condition.

- With the scaricator thus cocked, it is heldwith one hand by the barrel H andthe lower end In practice the application of the instrument tothe skin and the depression of the barrel to release the cocked mechanism is, it will be appreciated, a. single, swift, gentle movement.. The

downward. pressure required to release the mechanism is not great but insures that the instru-A ment is. applied to the body with sufficient. force to insure that head i2 is in irm contact with the: skin. No injury can occur through application of too much pressure inasmuch as,A the penetration. of the points 25 is in all cases. limited by the distance they project beyond. the plane ofL ,f the skin engaging face of head 12 it being understood further that they always are. releasedfor rotation when the downward pressure on the head reaches a. predetermined. Value- This insures that on successive operations of the scarificator, all scratches are of uniformv depth and Ytheir length obviously will always be the same. Thus, when a group of scratches are treated with differingv allergy test substances, a very reliable indication of the relative reaction of the patient to the variousv substances is obtained, no allowance having to be made for variations in the preparation of the skin for tests inasmuch as such variation is eliminated'.

Therapidity with which each scratch is made, coupled' with the Very superciai character of the scratch, makes it practically impossible for the patient to sense or feel the making of thev scratch. The sensory impression resulting from the' gentle pressure exerted by head I2 on the annular region around the knife, dominates that resulting from the scratching' operation itselfV to such an extent as to still further minimize the latter. For these reasons, the instrument eliminates a major diiliculty which heretofore has characterized scratch allergy tests, particularly inthe case of children and adults very sensitive tf1-pain.`

The depth of the scratch may easily be altered simply by .turning head l2 on. the stem Hl so that the points 25 extend below the plane of the skin-engaging surface a greater or lessy distance nostician in locating the area in which to apply the allergens. Except. for the advantages thus gained the annular ribs are,y of course, not absolutely essential, it being obvious that the skin-` engaging surface of the head l2 may be fiat or otherwise conflgurated.

with other advantages which are obvious which are inherent to the device.

It.will .be understood that certain features and subcombinations. This is contemplated by and is within the scope of the claims.

Inasmuch as many possible embodiments of the invention may be made without departing from the scope thereof, vit is to be understood.`

that all matter herein set forth or shown in the accompanying ldrawings is to be interpreted as illustrativeand not in a limiting sense.

Having thus described my invention, I claim:

1. In a scarificator, a support having a recess in one face th-ereof, a shaft rotatably mounted in said support and carrying a blade in said recess, the axis of the shaft being perpendicular to the plane of one face of the Support, said blade havingr a plurality of separate cutting edges spaced equidistant from said axis, all of said edges projecting out of said recess and extending the same distance beyond the plane of said one face, and means for rotating the shaft relative the support.

2. In a scarificator, a support having a recess in one face thereof, a shaft rotatably mounted in saidsupport and carrying a blade in said recess, the axis of the shaft being Aperpendicular to the plane of one face of thesupport, said blade having a plurality of separate cutting edges spaced equidistant from said axis, all of said edges projecting out of said recess and extending the same distance beyond the plane of said one face, means for rotating the shaft relative the support, and stop means limiting the rotation of said shaft to less than one complete revolution. 1

3. A scarificator comprising a rotatable shaft, a thin, fiat blade on the end of said shaft disposed in a plane passing through the axis of the shaft, said blade formed with a pair of integral prongs disposed on opposite sides of said axis and equidistant therefrom, the tips of said prongs lying along a line perpendicular to saidaxis.

4. A scaricator as in claim 3 wherein the end of said shaft is split axially to 4form two legs between which said blade is wedged and held by friction. v

5. Aiscaricator comprising a rotatable shaft, a thin, flat blade on the end ofsaid shaft disposed in a pla-ne passing throughthe axis of the shaft,lsaid blade formed with apair of integral prongs disposed on the opposite sides of said axis `and equidistant therefrom, the tips of said prongs lying along a line perpendicular to said axis, and a stationary skin-engaging shroud around the orbit of said tipslimiting the distance the tips can penetrate the skin.

6. `In a device of the kind described, a support having a recess in one face thereof, a shaft 1'0- tatably mounted in said sup ort and carrying a blade in said recess, the axis of the shaft being perpendicular to the plane of one face of the support, said blade having a cutting edge spaced laterally Vfrom said axis and projecting out of the recess beyond the plane of said one face, a source'of rotative power connected to said shaft tending to turn same about its axis, a stop hold- ,ingthe shaft against rotation, and mechanismcontrolled by the application of said one face of the support to an abutment surface to automatically withdraw said stop when the face is in firm contact with vthe surface.

7. Ina device of the kind described, a support having a recess in one face thereof, a shaft rotatably mounted in said support and carrying a` blade in said recess, the axis of the shaft being perpendicular to the plane of said one face of the support, said blade having a cutting edge spaced laterally from said axis and projecting out of the recess beyond the plane of said one face, a source of -rotative power connected to said shaft tending to turn same about its axis, a stop holding the shaft against rotation, said supporthaving a handle by which said one face of thesupport can be pressed against an abutment surface, and pressure sensitive means operative to withdraw said stop when the pressure of said one face on said surface reaches a predetermined value.

8. A device as in claim 7 wherein said one face of said support has thereon ribs arranged in a symmetrical pattern relative the axis of said shaft.

9. In a device of the kind described, a rotatable shaft journaled in a hollow stem, a head on one end of the stem having a face normal to the axis of the shaft and, in that face, a recess encircling the end of the shaft, a cutter in said recess secured to one end of the shaft for rotation therewith, said cutter having a, cutting edge projecting from the recess beyond the plane of said face, a barrel encircling the stem and slidable axially thereof, mechanism for rotating said shaft in said stem, and means connected to said mechanism and barrel to render said mechanism operative responsive to movement of the barrel axially of the stem.

l0. A device as in claim 9 wherein said head is screw threadedly secured to said stem whereby it is adjustable axially of the stem to vary the position of said one face relative to said cutter.

11. A device as in claim 9 having a pin and slot connection between saidr stem and barrel preventing rotation thereof relative to one another.

12. In a device of the kind described, a rotatable shaft journaled in a hollow stem, a head on one end of the stem having a face normal to the axis of the shaft and, in that face, a recess encircling the end of the shaft, a cutter in said recess secured to the end of the shaft for rotation therewith, said cutter having a cutting edge projectingv from said recess beyond the plane of said face, a barrel encircling the stem and slidable axially thereof, and a. latch between said shaft and barrel effective to permit or prevent rotation of the shaft in the stem depending upon the axial position of the barrel relative the stem.

13. In a device of the kind described, a rotatable shaft journaled in a hollow stem, a head on one end of the stem having a face normal to the axis of the shaft and, in that face, a recess encircling the end of the shaft, a cutter in said recess secured to the end of the shaft for rotation therewith, said cutter having a cutting edge projecting from the recess beyond the plane of said face, a source of rotative power connected to said shaft tending to rotate same in said stem, a barrel encircling the stem and slidable axially thereof, and a latch between said shaft and barrel effective to permit or prevent @was rotationk ofi" the shaft depending uponthe axialV position of the barrel relative the stem- 14. In a; device of the kind describe@ aA rotatable shaft journaled in a hollow stem; a head on one end of the stern having a, face normal to the .axis of the shaft and, in thatv farce,4 a.' recess encirclingV the end vof the shaft, a cutter in said, recess'secured to the end of' the shaft for roI tation therewith, said' cutter. having a cutting edge projecting from the recess beyond the plane of said one face, a barrel encircling the stem and slidable axially thereof, resilient yieldahlemeans between the stem: and barrel. urging the barrel away from said; head, a stop limiting the distance the barrei can move away from .the head whereby saidv barrel normaily occupies a predetermined position relative to' the. head, a.

source of rotative power eonnected'to` said shaft 8 tending to rotate same in said stem,y a, second stop holding said shaft againstrotation when. the barrel is in said predetermined position, said barrel being connected to said second stopl and eective to Withdraw'same when. the zlaiizel-is` shifted axially of the stem' Hom said prreteter position. against thev force Yot said. ye1dable means.

IRA. R. MORRISON'.n

manEmmonsy CITED 'The following references are of record in; the

file of this patent:

A UNITED STATES PATENTS 1,135,465 Pollock Apr, 13;, 1915i 

